The Micro LED display is becoming more and more attractive in the future. The LED used in the Micro LED display has a micrometer-order size, and has advantages such as individually controlled pixels, individually controlled light-emission, high brightness, low power consumption, high resolution and high chrominance. However, there are also many complicated and difficult technical issues to be solved in the Micro LED display, especially the mass transfer technology which is critical in the Micro LED display. With the development of technologies, multiple technical branches are developed from the mass transferring technology, such as the electrostatic adsorption technology and the laser technology.
In a conventional micro LED mass transferring method, a micro element is transferred from a transferring substrate to a receiving substrate through wafer bonding. The transferring method includes a direct transferring method and an indirect transferring method. In the direct transferring method, a micro element array is directly bonded to the receiving substrate from the transferring substrate, then the transferring substrate is removed. In the indirect transferring method, the bonding/stripping step is performed twice, parts of a micro element array located on an intermediate substrate are picked up by the transferring head, and are bonded to the receiving substrate, then the transferring head is removed.
However, in the conventional mass transferring technology including the direct transferring method and the indirect transferring method, the Micro LED is detected via a detecting circuit after the bonding of the Micro LED to the receiving substrate, and the Micro LED is replaced or repaired in a case that the Micro LED emits light abnormally, which results in a complicated detecting and repairing processes.